Palin's backing offers Hatch another conservative endorsement as he holds off a Republican primary challenge from former state Sen. Dan Liljenquist. Hatch, who has faced criticism from some conservatives for past votes, narrowly missed securing the nomination at the state party convention last month, forcing the two into a June 26 primary.

Palin announced the endorsement first Tuesday night on Fox News' "On the Record With Greta Van Susteren," then posted a long comment on her own Facebook page.

"Orrin Hatch is a life-long conservative whose dedication and devotion to the conservative cause and to his beloved and beautiful state of Utah is well documented," Palin wrote on her Facebook page. "Orrin was a Utah state campaign chairman for a fledgling and failing presidential candidate deemed 'too conservative' and 'unelectable' by the media. Ironically, that candidate was the man who restored our country to be a 'shining city on a hill' — Ronald Reagan."

"I join other conservatives like Mark Levin, Sean Hannity, and Tea Party leaders like Sal Russo in encouraging Utah voters to return Orrin Hatch to the U.S. Senate," she added.

Whoever wins the primary will be heavily favored to hold the seat. Roll Call rates the general election race as Safe Republican.